CAID is built around the workgroup concept. Each workgroup contains an inspector and a viewer. In the future, it will also contain solvers as well as diagnotics modules.
This is where you can navigate/manipulate all geometries objects. Each geometry object contains a list of patchs and some additional informations, like the connectivity, internal/external faces. A geometry is simply the « cad_geometry » object that you can get from the igakit package.